Description

The License Disconnect Timeout period is duration after which the License server is hard coded to automatically check-in licenses from clients that have been disconnected, so that they can be used by other users.  This value is a hard-coded into the License Manager and varies by Ansys version:

• 2023 R2 and Prior - 2hrs (effectively ~2-2.5hrs due to heartbeat intervals)
• 2024 R1 & R2 - 3min (yes, it went from 2hrs to 3min.  Abandoned/Ghost License bug still exists)
• 2025R1 and Later - 3min, (Abandoned/Ghost License bug resolved)
   

Important Related Articles

• INFO - What happens when you lose connection to an Ansys license server?
• HOW TO - Enable the Ansys Idle Timeout Feature 
• ERROR - Cannot return a borrowed license
• HOW TO - Release a Stuck/Reserved/Abandoned License 
   

Important Terms

• Heartbeat - Every ~5min-10mins (hard coded and not adjustable), the client software checks-in with the server to ensure it keeps the license reserved.  It's basically saying, I'm still here, don't give my license to anyone else.  If the client can't reach the license server, it's considered disconnected and will retry every ~5-10min for up to 60min, displaying an error message every ~5-10min of this countdown.  At the end of this countdown, the software will be placed into read-only mode. Learn more about this - INFO - What happens when you lose connection to an Ansys license server? 
• Reserved License - a license that is actively checked-out and in use by a client.
• Released License - a license that is available to be checked-out/reserved. When the client software closes gracefully or stops needing a license, it will be checked back in at that time, releasing the reservation it has on it.  If the client application crashes or loses connectivity with the license server, this reservation will be automatically released by the license server after the License Timeout Period.
• Stuck License - a license that is permanently stuck in the reserved state, even after the client has been disconnected for the License Disconnect Timeout period, due to a software glitch.
• Abandoned/Ghost Licenses - a term used to describe a license that is reserved by a client that has disconnected and then reconnects under a new “client ID”, and as a result, checks out a new license and does not utilize the previous license reservation.  This results in extra, unintended; licenses being consumed.  The original reservation will be released after the License Disconnect Timeout Period.  This is caused by a bug in the FlexNet code and can occur in several scenarios: 
  • A client disconnects and then reconnects from a new network adapter such as going from Ethernet to WiFi.
  • A client disconnects and then reconnects after going from the office network to a home network using a VPN.
  • A client is using a VPN and it disconnects and then reconnects.  Even this establishes a new client ID.
    Note:  This bug is scheduled to be resolved in 2025R1.